Field of the Invention
The present invention relates to an X-ray data processing apparatus for estimating a true value from a counted value for X-ray intensity of a specific X-ray source and to a method and program for the same.
Description of the Related Art
In a pixel array detector of a photon counting system, typically a monolithic sensor is used and therefore a definite boundary does not exist between pixels within the sensor. Typically only a read-out pad portion is formed in a pixel shape on the side connected to a read-out chip (refer to Patent Literature 1).
Therefore, when a carrier diffuses in a boundary part of neighboring pixels, there occurs a phenomenon called charge share in which a charge corresponding to one photon is shared between the pixels. Because of this charge share, even if the intensity of an incident X-ray is constant, there exists a case where the count becomes larger than an original count or a case where the count becomes smaller than the original count, depending on a threshold value set for each of the pixels.
While, conventionally, measurement has been performed neglecting the influence of the charge share, or the measurement has been performed minimizing the influence by setting an appropriate value to the threshold value, such a method cannot remove the effect of the charge share. On the other side, there has been performed a study of mounting a circuit for cancelling the influence itself of the charge share between pixels in the read-out chip (refer to Non-patent Literature 1).